In its heart GT Walsheim is a geometric grotesk, but it also has a certain handmade roughness engrained in its design. Based on custom typography by Otto Baumberger for multiple lithography posters from the early 20th century, Walsheim is suitable both for display and for text use.

Baumberger was one of the great early Swiss poster designers. Baumberger stated that he never really had an education in typography. He invented his own typefaces as he needed them while designing his posters. At first the type used on the posters seem to be random experiments, but once you take a closer look, you realize that they share certain design aspects which occur throughout most of his work. Especially the peculiar uppercase G with its very unique design is interesting. Many posters by Otto Baumberger show type with the same G and very similar overall characteristics.